Chloroisocyanuric acids such as trichloroisocyanuric acid (also referred to as "TCCA," or by its more formal chemical name trichloro-s-triazinetrione) is effectively used as a sanitizer for recreational water systems such as swimming pools, spas, hot tubs, etc. Solid TCCA is commonly compressed into tablets or pucks that are convenient to use, and provide the benefit of dissolving slowly and uniformly in water to continuously release the sanitizer over long periods of time. TCCA is rarely compressed with other chemicals that may be oxidized or which promote the decomposition of TCCA. This is due to the safety hazard associated with compressing TCCA, a strong oxidizer, with other chemicals.
A variety of other agents such as aluminum sulfate and sodium tetraborate are also known to provide beneficial properties to water. For example, hydrated aluminum sulfate (alum) is used to clarify water due to its ability to flocculate or precipitate impurities in the water. The flocculated or precipitated impurities are normally larger than the original impurity and, as a result, the impurities are more readily removed via water filtration.
In addition, flocculants provide the additional benefit of reducing the demand on oxidizers or sanitizers in the water. The materials that are flocculated by alum and other such flocculants are commonly organic in nature. Since the flocculant helps remove these organics from the water, less oxidizer is needed. Consequently, lower oxidizer/sanitizer levels (chlorine, bromine, hydrogen peroxide, ozone, etc.) are needed to keep the water clean and safe.
Boron derivatives like borax, boric acid, etc., are also known to provide beneficial properties to water. For example, boron-containing compounds such as borax are known to provide algicidal and fungicidal properties to water when maintained at appropriate levels.
Unfortunately, both alum and borax are both highly water soluble, and the addition of water-soluble additives to trichlor is known to either increase trichlor's water dissolution rate or cause the tablets to prematurely disintegrate or collapse. This rapid dissolution of trichlor is generally undesirable and inconvenient since users are then required to add product more frequently to maintain the desired level of residual chlorine in the water.
A need therefore exists for a method of incorporating water-soluble compounds such as alum and borax into solid trichlor sanitizer pucks that do not either disintegrate or dissolve more quickly than trichlor itself. The present invention addresses that need.